Testing instrument.



H. BALUSS.

TESTING INSTRUMENT.

APPLICATION nun JULY 23, 1910.

1,104,753. Patented July 21, 1914 WITNESSES jbw Mow M/ZVE/VTOR adM m mum IBALUSS, or KEuNn'rr' SQUARE, mms'uvim, ASSIGNOR arc-THE I mmcau STEEL & v

rom'rrou or NEW JERSEY.

wmn comrhNY, or; nonoxnu, unwannsnmafcona 'rns'rme iusrnnmsu'r.

To all whom it may concern Be it lmown' that I,-HAMILTON ALUss, a citizen of the United States, residin in Kennett Square, Pennsylvania, have invented certain new and useful Improvements in Testing Instruments, of which the following is a specification.

. This invention aims to, provide an ink.

proved apparatus adapted for testing electrical joints especially for testing the chiciency of rail bonds such as are commonlyused for making electrical connection between the ends of railway rails. q A specific object of-the invention is todetermine whether'any' given rail joint is of less, greater or equal electrical resistance with respect to that of a predetermined standard;

The accompanymg drawing represents, with the electrical parts In diagram, an embodiment of the invention.

Referring to the specific embodiment of the invention illustrated the rails A and B are. connected by abond O which is to be tested. This is doneby passingfa current, independent of. the, propulsion current 111 the rails, which for the sake of dlstinctionI call a main current, through the bond and shunting apart of the main current around the bond and comparing 'therelative strengths of the main and shunt currents. .The contacts are made by means of a hand tool or holder and which may be used either with the electrical apparatus described or with various other electrical apparatuses. It comprises four contacts D, E, F and G arranged in pairs; the first two, for

engagement with the rail A, being carried on a short holder H of'wood or other non-conducting material and the second pair and G, for the rail B, beingcarried by a similar holder J. A bar K also of wood or other non-conducting material is provided with a handle Land carries the two shorter bars H and J, each ofthese being connected; at an intermediate point of its length through a link M with the long bar K. By means of the handle L the operator can shiftthe contact holder easily so as to place it in the correct position upon the rail. By bearing down on the bar K the two shorter bars are "pressed down and the link serves as an Specification of Letters Patent.

equalizer to distribute the pressure to the contacts of each pair. The several contacts D, E, F and G are connected by wires H, O, P and Q to'mechanism carried in or upon a 1 box R which is thus flexibly connected with r the contact holder so that the operator-may sling the box over his shoulder and carry the a contact holder in one hand and thus proceed rapidly from joint to joint as well as quickly pick upthe apparatus and set it down. The

contacts may be: of any suitable form and material and attached in any suitableway to then supporting bars. Thev are preferablysharp steel points, the shanks of which-are screwed or bolted into the bars. The piv-:

otal connection of the bars H and to the long bar K equalizes any differences in the level between the tops of the two rails.

The box R carries a primary battery S, preferably of two or three dry cells; andthe battery is in a circuit comprising a magnetic vinterrupter, such for mstance, as a small buzzer T, a switch U, wire Q, contact G, the rails and the bond, contact D and wire N; the contacts D and G being called the main contacts. The magnetic interrupter is a simplified construction of an electric buzzer which rapidly interrupts and remakes the circuit, and produces a magnetic field. Adjacent to it is an induction coil of the type used for telephones and comprising an adjustable iron core V, a primary coil W- and a secondary coil X in circuit with a telephone receiver Y, the latter' being connected either permanently or by binding posts to which it is attached. The primary W of the induction coil is in circuit through a switch Z with the wires 0 and P so as to form a shunt around the bond by way of the contacts E and F. The telephone may be provided with a headpiece for securing it to the operators ear, or not, as desired. The several switches of the apparatus convenient point.

The direction of flow of the current in the main and shunt circuits is as follows: As suming-that thecurrent in the main circuit flows from the battery to the interrupter, it then passcs'through switch U, the wire Q, contact Gr, rail B, bond C, rail A, contact D and wire N backto battery. In the shunt Patented July 2 1,"1914. Application filed m 23, 910. Serial No. 573,418; a

may be placed upon the box or at any other circuit, the .currentsplits from the main circuit at F, passes through wire P to the primary of the induction coil W, swltch Z and wire 0 to contact E, rail A, contact D and wire N of the main circuit.

The instrument is not designed to give the ohmicresistance, but merely to determine whether the resistance is greater or less than a standard amount for which-the instrument is adjusted. This may be illustrated by the manner of adjusting the .instrument. The instrument is put in position upon a joint whose resistance is as high as is permissible without rebonding. This is referred to herein as the standard of resistance. While upon such a joint of standard resistance the instrument is calibrated as hereinafter described until thevolume of the sound (not the tone is equal when the switch Z is open and W en it is closed.

This is readily determined by a few trials.

If the instrument is placed, after adjusting, upon a joint of less resistance than the standard the sound with the switch Z closed is fainter, than with such switch open. If placed upon a joint of greater resistance than the standard the sound is greater with the switch Z closed.

The reasons why the sound, with the switch Z closed is reater (relativel to the sound with the switch open) for a oint of greater resistance, and fainter for a joint of less resistance, are the following: with the shunt O, P open at Z, the only sound produced by the receiver Y is that due to the actionof the stray magnetic field of the buzzer on the induction coil, and this sound will remain nearly constant (with the shunt O P open) on all joints which are not entirely open-circuited. On the other hand, supposin the shunt O, P closed at Z, a part of t e current passes through the induction coil W, the direction of the shunted circuit having been hereinbefore dedrawing. In case the rail joint is reason- -ably well bonded, the joint substantially short circuits the contacts E and F and allows only a small portion of the total amount of current'to pass through the induction coil W. This is so because the wire conductor portion of this shunt circuit offers a high resistance compared to that of a well bonded rail joint. With the switch Z closed, therefore, a current will be passing through the buzzer circuit and also through the transformer circuit, and while the current passing through the transformer circuit may be small, it would still have a very decided efi'ect upon the secondary of the induction coil, as compared with the effect thereon of the flux due to the buzzer. In other words, the effect of the induction coil, with even a very small current, is

scribed and indicated by arrows on the either the buzzer or thecoil.

greater than and is opposed to the effect of the buzzer, wherefore the induction coil predominates, and the sound produced with the switch Z closed is due to the predominant effect of the induction coil over that of the buzzer. When the switch Z is open, the sound is due to the. effect on the induction coil of the flux produced by the buzzer.

To calibrate the device, it is placed upon a joint having a predetermined resistance, which will be knownas the standard resistance. The buzzer, being flexibly mounted and connected with the main circuit, is then moved into various positions'until the volume of the sound (not tone) is the same with the switch Z open as it is with the switch Z closed.- If this position is not found in a minute or so, then the connections of the buzzer are reversed, and when the'buzzer has beenplaced in such a position that the volume of sound with the switch Z closed is equal to the volume of sound with the switch Z open, then all the electrical connections are correct, and the instrument is properly calibrated for a bond of predetermined standard resistance. It will now be quite apparent that the sound with the switch open is due entirely to the effect on the induction coil of the flux produced by the buzzer, while the sound with the switch Z closed is due, not to the cumulative effect of the current passing through the shunt circuit and the effect of the flux produced by the buzzer, but to the predominant effect of the current passing through the induction coil over and in opposition to that produced by the flux of the buzzer. It will be understood that if the effects of the induction coil and of the flux produced by the buzzer were cumulative, then no point of equal volume of sound could be found,

because when the switch is closed the vol- .rious positions with respect to the buzzer,

or by varying the distance between the buzzer and the induction coil, which adjustments will change the amount of induction in the secondary coil from the action of the buzzer and will change the sound of the receiver. The same' effect can be brought about by placing a damper on or thin sheet of iron between the buzzer and the inductioncoil and shifting its plane with respect to The induction coil can be adjusted by shifting the core V or in any other usual or suitable way.

Another and very simple method of varying the effect of the buzzer on the induction coil is to provide a second buzzer T with a switch U' (the switches U and U being separately operable) the second buzzer being designed to have a different effect upon the induction coil from that produced by the first buzzer; and switching in either buzzer or both, according to need. Where a second buzzer is not to be used there is no need for the switch U since the buzzer T may be permanently connected to the wire Q. The

sensitiveness of the instrument can be further varied by varying the number of electrical cells in the circuit or by making the receiver more or less sensitive.

In using the present instrument, it is placed in position, as illustrated in the drawing, with the contacts G and F on one rail, and the contacts E and Don the abutting rail. The switch Z being open, the telephone receiver Y is placed to the ear and a mental note is made of the volume of sound produced by the receiver. The switch Z is then closed and the sound given oif by the receiver Y is again noted. If the volume of sound with the switch Z open is the same as with the switch Z closed, then the bond C is of standard resistance, because the instrument has been calibrated to produce equal volumes of sound with the switch Z open and closed when applied to a joint having a bond of standard resistance. If, however, the volume of sound produced with the switch Z closed is greater than that produced with the switch Z open, then the bond is of greater resistance than standard, for

the reason that, with the bond of greater re-- sistance, a larger amount of current will be shunted through the circuit 0, P, and consequently the predominating efiect of the induction coil will be greater and the sound given 01f by the telephone receiver Y will be greater. On the other hand, if the sound given ofi' by the receiver Y is less with the switch Z closed than with the'switch Z open, the bond C is of less resistance than standard, for the reason that the resistance of the shunt circuit 0, P being greater than the resistance of the rail bond 0, a smaller amount of current will pass through the shunt circuit 0, P than. with a bond of standard resist-- ance, and consequently the predominating effect of the current passing through the shunt circuit on the induction coil over that produced by the flux of the buzzer is less than with a bond of standard resistance.

The connections of the handle L to the bar K near its end leaves the middle free so that the operator can put his foot on it and press with substantially his whole weight on the contact, a good connection at the several points being of considerable importance.

can be used whether or not a return current is flowing and whether such a current be continuous or alternating.

Tho-ugh I have described with great particularity of detail certain specific embodiments of my invention, yet it is not to be understood therefrom that the invention is restricted to the complete apparatus specifically described. Various modifications, therefore, in whole or in part may be made by those skilled in the art without departure from the invention.

What I claim is:

1,. A testing instrument for rail bonds and the like comprising means for passing a main current through the bond, means for shunting a current around the bond, and a telephone receiver actuated ditferently by the two different currents.

2. A testing instrument for rail bonds and the like comprising means for passing a main current through the bond, means for shunting apartof the main current around the bond, an interrupter actuated by the main current for generating a magnetic field, a telephone receiver having a circuit passing through said magnetic field and an induction coil in the circuits of the shunt current and the receiver.

3. A testing instrument for rail bonds and the like comprising a circuit in which is an interrupter adapted to generate a magnetie field, rail contacts for said circuit, another circuit passing through said magnetic field, rail contacts for said other circuit, an indicator in operative relation to the two circuits, and means for adjusting the eifect of said interrupter upon said other circuit.

4. A testing instrument for rail bonds and the like comprising a circuit and an interrupter therein for generating a magnetic field, rail contacts for said circuit, another circuit passing through said magnetic field,

rail contacts for said other circuit, a telephone receiver in operative relation to the two circuits, and means for adjusting the effect of the interrupter upon said other circuit.

5. A testing instrument for rail bonds and the like including four contact points in pairs, a separate holder for each pair and a bar to which an intermediate point of each holder is pivotally attached.

6. A testing instrument for rail bonds and the like including four contact points in pairs, separate holders H and J one for each pair, a barK having a handle and having a pivotal connection to each oft-he holders H and J at an intermediate point of the length of the holder,

7. A testing instrument for rail bonds or the like comprising an induction coil, wires for connecting said coil between points at opposite sides of the bond, a battery, means for generating a magnetic field and wires for connecting said battery and said means for generating a magnetic field between points at opposite sides of the bond, said induction coil being in position to be influenced by said magnetic field.

8. A testing instrument for rail bonds or the like comprising an induction coil, wires for connecting said coil between points at opposite sides of the bond, a battery, means for generating a magnetic field and wires for connecting said battery and said means for generating a magnetic field between points at opposite sides of the bond, said induction coil being in position to be influenced by said magnetic field connected to said wires and a holder carrying said contacts.

9. A testing instrument for rail bonds or the like, comprising an indicator, two electric circuits in operable relation thereto, and means controlled by the circuits for actuating the indicator to substantially the same degree under the combined influence of the circuits and under the influence of one of the circuits when used upon the bonded joint of standard resistance.

10. A testing instrument for rail bonds and the like, comprising a main circuit having rail contacts disposed to include the rail bond to be tested, a shunt circuit to shunt said main circuit with respect to the rail bond, an indicator associated with the two circuits for actuation thereby for indicating the relation, above or below a standard resistance, of the resistance of the bond being tested, and means to subject the indicator to the action of one of the circuits and also to the simultaneous action of both. of the circuits.

In witness whereof, I-have hereunto signed my name in the presence of two subscribing witnesses.

HAMILTON BALUSS. lVitnesses 7 J. J. NILAN, JOHN T. Dow). 

